Medicine and Health Sciences Commons^™

Molecular Brain Adaptations To Ethanol: Role Of Glycogen Synthase Kinase-3 Beta In The Transition To Excessive Consumption, Andrew D. Van Der Vaart

Theses and Dissertations

Alcoholism is a complex neuropsychiatric disease that is characterized by compulsive alcohol use and intensifying cravings and withdrawals, often culminating in physiologic dependency. Fundamental alterations in brain chemistry underlie the transition from initial ethanol exposure to repetitive excessive use. Key mediators of this adaptation include changes in gene expression and signal transduction. Here we investigated gene expression pathways in prefrontal cortex and nucleus accumbens following acute or chronic ethanol treatment, to identify genes with potentially conserved involvement in the long-term response of the corticolimbic system to repeated ethanol exposure. We investigated Gsk3b, which encodes glycogen synthase kinase 3-beta, as a …

Advances In Dual-Energy Computed Tomography Imaging Of Radiological Properties, Dong Han

Theses and Dissertations

Dual-energy computed tomography (DECT) has shown great potential in the reduction of uncertainties of proton ranges and low energy photon cross section estimation used in radiation therapy planning. The work presented herein investigated three contributions for advancing DECT applications. 1) A linear and separable two-parameter DECT, the basis vector model (BVM) was used to estimate proton stopping power. Compared to other nonlinear two-parameter models in the literature, the BVM model shows a comparable accuracy achieved for typical human tissues. This model outperforms other nonlinear models in estimations of linear attenuation coefficients. This is the first study to clearly illustrate the …

Heparan Sulfate, A New Target For Platinum In Metastatic Tnbc, Samantha J. Katner

Theses and Dissertations

Abstract

Heparan Sulfate, A New Target for Platinum in Metastatic TNBC

Author: Samantha J. Katner, Ph.D.

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy

Virginia Commonwealth University, 2018

Advisor: Dr. Nicholas Farrell, Professor, Chemistry Department

Heparan sulfate proteoglycans (HSPGs), composed of the linear polysaccharide heparan sulfate (HS) conjugated to a protein core, are located on the cell surface and extracellular matrix. The HS chains display varying degrees of sulfation, which constitutes the molecular recognition motif for many HS-protein interactions. HSPGs, associated growth factors, and heparanase promote tumor progression by facilitating invasion, angiogenesis, …

Age-Dependent Changes In Oxygen Supply And Demand Of Rat Spinotrapezius Muscle, Sami C. Dodhy

Theses and Dissertations

Because of the aerobic nature of cellular metabolism in mammalian organisms, a continuous supply of oxygen is necessary to maintain normal physiological function. As organisms age, their metabolic rates generally decline and there are accompanying alterations in the structure and function of the microcirculation, as this part of the cardiovascular system is especially important for oxygen exchange. The overall Oxygen Transport System can be considered as being composed of two complementary components: one for Oxygen Demand and one for Oxygen Supply. The purpose of the current work is to describe the age-dependent changes in both oxygen demand and oxygen supply …

In Vitro Genetic Code Expansion And Selected Applications, Emil S. Iqbal

Theses and Dissertations

The ability of incorporation non-canonical amino acids (ncAAs) using translation offers researchers the ability of extend the functionality of proteins and peptides for many applications including synthetic biology, biophysical and structural studies, and discovery of novel ligands. Here we describe the three projects where the addition of ncAAs to in vitro translation systems creates useful chemical biology techniques. In the first, a fluorinated histidine derivative is used to create a novel affinity tag that allows for the selective purification of peptides from a complex mixture of proteins. In the second, the high promiscuity of an editing-deficient valine-tRNA synthetase (ValRS T222P) …

The Influence Of Clinically Meaningful Factors On The Performance Of The Recommended Annual Diabetic Foot Screening, Trisha A. Sando

Theses and Dissertations

Background: Diabetic foot ulcers are the result of multiple complications from hyperglycemia and lead to poor quality of life and high healthcare costs. The annual diabetes foot screening exam (ADFSE) and prevention interventions can reduce DFUs up to 75%. In 2015, 71% of the US population received the ADFSE.

Objectives: The main objectives of this dissertation were: 1) to determine the association between adherence to diabetes self-management behaviors and the ADFSE, 2) to determine the association between concordant and discordant comorbidities and the ADFSE and 3) to determine the association between the performance of diabetes preventive care processes, number of …

Drug Delivery With Light, Patrick S. Dupart

Theses and Dissertations

Cancer is responsible for about 25% of deaths in developed countries and for 15% of all deaths worldwide. Cancer is a devastating disease and while there have been great advances in the development of anticancer drugs, off-target toxicity is a major limitation with conventional cancer chemotherapy. The consequence of this form of treatment results in the killing of healthy and rapidly-growing non-cancerous cells including cells in the bone marrow; hair follicles; and cells in the mouth, digestive tract, and reproductive system. In addition to these general effects, certain anticancer drugs can have other associated toxicities. For instance, the anticancer drug …

Orthodontists’ And Patients’ Preferences In Website Design In The Selection Of An Orthodontic Practice: A Comparative Study, Taylor R. Brown

Theses and Dissertations

Objective: To determine which website characteristics are preferred by orthodontists, adult patients, and parents of patients.

Materials and Methods: 1,000 active members of the American Association of Orthodontists and 750 active orthodontic patients/parents were sampled. Participants rated the importance of website characteristics, indicated presence of those characteristics on the current website, and ranked sample website images. Preferences were compared between orthodontist and the patient/parent group using t-tests and sample websites were compared using ANOVA models and Tukey’s adjusted post-hoc tests. Significance level was set at 0.05.

Results: 11 of the 16 website features showed significant differences between patients/parents and orthodontists. …

Development Of Novel Models To Study Deep Brain Effects Of Cortical Transcranial Magnetic Stimulation, Farheen Syeda

Theses and Dissertations

Neurological disorders require varying types and degrees of treatments depending on the symptoms and underlying causes of the disease. Patients suffering from medication-refractory symptoms often undergo further treatment in the form of brain stimulation, e.g. electroconvulsive therapy (ECT), transcranial direct current stimulation (tDCS), deep brain stimulation (DBS), or transcranial magnetic stimulation (TMS). These treatments are popular and have been shown to relieve various symptoms for patients with neurological conditions. However, the underlying effects of the stimulation, and subsequently the causes of symptom-relief, are not very well understood. In particular, TMS is a non-invasive brain stimulation therapy which uses time-varying magnetic …

Motion-Induced Artifact Mitigation And Image Enhancement Strategies For Four-Dimensional Fan-Beam And Cone-Beam Computed Tomography, Matthew J. Riblett

Theses and Dissertations

Four dimensional imaging has become part of the standard of care for diagnosing and treating non-small cell lung cancer. In radiotherapy applications 4D fan-beam computed tomography (4D-CT) and 4D cone-beam computed tomography (4D-CBCT) are two advanced imaging modalities that afford clinical practitioners knowledge of the underlying kinematics and structural dynamics of diseased tissues and provide insight into the effects of regular organ motion and the nature of tissue deformation over time. While these imaging techniques can facilitate the use of more targeted radiotherapies, issues surrounding image quality and accuracy currently limit the utility of these images clinically.

The purpose of …

The Role Of Adam10 And Adam17 In Humoral And Type 2 Immunity, Joseph C. Lownik

Theses and Dissertations

The proper regulation of inducible costimulator (ICOS) and its ligand (ICOSL) have been shown to be essential for maintaining immune homeostasis. Loss of either protein results in defective humoral immunity, and overexpression of ICOS results in aberrant antibody production resembling lupus. How ICOSL is regulated in response to ICOS interaction is still unclear. We demonstrate that ADAM10 is the primary physiological sheddase of ICOSL in both mouse and human. Using an in vivo system in which ADAM10 is deleted only on B cells (ADAM10^B-/-), elevated levels of ICOSL were seen. This increase is also seen when ADAM10 is …

Evaluation And Adaptation Of Live-Cell Interferometry For Applications In Basic, Translational, And Clinical Research, Kevin A. Leslie

Theses and Dissertations

Cell mass is an important indicator of cell health and status. A diverse set of techniques have been developed to precisely measure the masses of single cells, with varying degrees of technical complexity and throughput. Here, the development of a non-invasive, label-free optical technique, termed Live-Cell Interferometry (LCI), is described. Several applications are presented, including an evaluation of LCI’s utility for assessing drug response heterogeneity in patient-derived melanoma lines and the measurement of CD3+ T cell kinetics during hematopoietic stem cell transplantation. The characterization of mast cells during degranulation, the measurement of viral reactivation kinetics in Kaposi’s Sarcoma, and drug …

Housing Status, Patient Characteristics, And Ed Utilization Associated With Medication Prescribing At Ed Discharge Among Homeless And Nonhomeless Adults In Urban Hospitals In The United States, Lauren Cox

Theses and Dissertations

This cross-sectional study used a weighted sample of ED visits contained in the 2010-2015 years of the National Hospital Ambulatory Care Survey-Emergency Department (NHAMCS-ED) dataset. The purpose of this study was to: 1) identify differences in predisposing, enabling, and need characteristics, and ED use and medication prescribing characteristics between homeless and nonhomeless ED users; 2) assess the association between housing status and medication prescribing at ED discharge, and identify variables contributing to the disparity in medication prescribing between homeless and nonhomeless ED users; and 3) assess the predisposing, enabling, need, and ED use characteristics that predict medication prescribing at ED …

Effects Of Hiv-1 Tat And Drugs Of Abuse On Antiretroviral Penetration Inside Different Cns Cell Types, Sulay H. Patel

Theses and Dissertations

Human immunodeficiency (HIV) infection can result in neurocognitive deficits in about one-half of infected individuals. Despite excellent systemic effectiveness, restricted antiretroviral penetration across the blood-brain barrier (BBB) is a major limitation in fighting HIV infection within the central nervous system (CNS). Drug abuse exacerbates cognitive impairment and pathologic CNS changes in HIV-infected individuals. This work investigates the effects of the HIV-1 protein, Tat, and drugs of abuse on factors affecting drug penetration into the brain.

Firstly, an in vitro model of the blood-brain barrier was built to study effects of HIV-1 Tat and methamphetamine (Meth) on integrity and function of …

Accuracy Of A Smartphone-Based Orthodontic Treatment Monitoring Application, Heather Moylan

Theses and Dissertations

Objectives: Dental Monitoring® (“DM,” Dental Monitoring, Paris, France), is a cloud-based software that allows orthodontists to track patients’ treatment remotely. The purpose of this study was to investigate the accuracy of the software in making linear measurements.

Methods: Patients took intraoral photographs using the DM application, immediately followed by impressions for plaster models. Intercanine and intermolar width and arch depth measurements were made by DM and compared to measurements made on the plaster models. Data was analyzed using two one-sided t-tests for equivalence with equivalence bounds of

+/-0.5mm. Significance level was set at 0.05.

Results: Thirty sets of measurements were …

A Comparison Of Quality Indicators Between Medicare Accountable Care Organizations And Health Maintenance Organizations Using Publicly Available Data, William W. Campbell Iii

Theses and Dissertations

The purpose of this study is to explore differences in quality between Medicare Accountable Care Organizations (ACO) and Health Maintenance Organizations (HMO). Three outcomes measures reported by these plans use different methodologies but possess enough alignment to permit comparison: percent of diabetic patients with last HbA1c > 9.0%, colon cancer screening rate and ER visits per 1,000. These outcomes are the dependent variables (DV). A secondary purpose is to explore differences in quality based on the size of the beneficiary population served, using the same measures.

As the Medicare program faces threats to its solvency in coming decades, with 10,000 baby …

Directing Mesenchymal Stem Cells For Periodontal Regeneration, Charles Stoianovici

Theses and Dissertations

Background: Directing autogenous Mesenchymal Stem Cell (MSC) to defect sites has a great promise in bone regeneration. We designed a MSC specific, bone affinity peptide (E7HA7) by conjugating E7 with a polyglutamate hydroxyapatite (HA) binding motif. We sought to characterize the in-vivo releasing pattern and bioactivity of E7HA7. Methods: HA discs were coated with fluorescent labeled peptides E7HA7, E7HA2 or E7 were subcutaneously implanted in Sprague Dawley rats. In an ectopic bone formation model was used to test the in-vivo bioactivity of E7HA7 conjugated to DBM. Results: E7HA7 showed slower peptide release from scaffolds in comparison to other groups, being …

The Effects Of Amixicile On Sub-Gingival Biofilm Cultured From Humans, Kian Azarnoush

Theses and Dissertations

Periodontitis is an inflammatory disease of the oral cavity induced by anaerobic bacteria, that remains to be the primary cause of tooth loss in adults worldwide. Finding an anti-microbial therapeutic to selectively target periodontal pathogens has proven to be difficult, and current treatment modalities only provide a transient benefit. Amixicile is a non-toxic, readily bioavailable novel antimicrobial that targets strict anaerobes through inhibition of the activity of Pyruvate Ferredoxin Oxidoreductase (PFOR), a major enzyme mediating oxidative decarboxylation of pyruvate, a critical step in metabolism. Our study aimed to evaluate the efficacy of amixicile in inhibiting the growth of bacteria harvested …

Understanding The Role Of Phosphoinositide 3-Kinase And Its Function As A Driving Force Behind The Er Stress Response In Fibrostenotic Crohn’S Disease-Affected Ileal Smooth Muscle Cells, Prashant Yadav

Theses and Dissertations

Crohn’s disease (CD) affects about 780,000 people in the United States alone, and it is estimated that 6-15 per 100,000 persons will receive a diagnosis of this disease each year. There currently is no cure for Crohn’s disease, and available medical therapies simply serve to alleviate the inflammation. This does not help treat fibrostenosis that Crohn’s disease patients may develop, which can only be treated surgically. Finding alternatives to treat CD requires an understanding of mechanisms at the biochemical level. In this thesis, we attempted to gain a better understanding of certain pathways found to be active in Crohn’s disease-affected …

Advanced Imaging Analysis For Predicting Tumor Response And Improving Contour Delineation Uncertainty, Rebecca N. Mahon

Theses and Dissertations

ADVANCED IMAGING ANALYSIS FOR PREDICTING TUMOR RESPONSE AND IMPROVING CONTOUR DELINEATION UNCERTAINTY

By Rebecca Nichole Mahon, MS

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University.

Virginia Commonwealth University, 2018

Major Director: Dr. Elisabeth Weiss,

Professor,

Department of Radiation Oncology

Radiomics, an advanced form of imaging analysis, is a growing field of interest in medicine. Radiomics seeks to extract quantitative information from images through use of computer vision techniques to assist in improving treatment. Early prediction of treatment response is one way of improving overall patient care. This work …

Economic Burden Of Renal Cell Carcinoma (Rcc) And Treatment Patterns, Overall Survival And Healthcare Costs Among Older Metastatic Rcc Patients, Hrishikesh P. Kale

Theses and Dissertations

Background

Renal cell carcinoma (RCC) is the most common type of kidney cancer. Patients diagnosed with metastatic RCC (mRCC) have shorter overall survival compared to those diagnosed at earlier stages. Several targeted therapies, which cost from $7,000 - $16,000 per month have been approved since 2005 to treat mRCC. In addition, there is a growing interest in the use of cytoreductive nephrectomy (CN) with targeted therapies among mRCC patients. However, little is known regarding the economic burden of RCC and role of CN and prescribing patterns of targeted therapies among older mRCC patients.

Objectives

1) To assess the economic burden …

The Periodontal Specialty: A Survey Regarding Our Future, John H. White

Theses and Dissertations

Purpose: To determine the characteristics influencing periodontal practices in Virginia and report on the anticipated changes in practice.

Methods: A REDCap survey was emailed to Virginia based American Academy of Periodontology (AAP) members assessing personal and practice demographics, trends in dental treatment and practice models, and how periodontists will adjust to account for these trends.

Results: The response rate was 31% (n=46). Respondents report greater referrals from more experienced general practitioners (GPs). Student debt was associated with age. Respondents ranked biologic advances, treatment of peri-implantitis, digital dentistry, development of corporate and group practice models, and GPs incorporating more periodontal …

Influence Of Muscle Strength On Mobility In Critically Ill Adult Patients On Mechanical Ventilation, Audrey R. Roberson

Theses and Dissertations

Patients in the intensive care unit (ICU) setting are prone to develop muscle weakness and the causes are multi-factorial. Muscle strength in adult, critically ill patients on mechanical ventilation decreases with immobility. The influence of muscle strength on different muscle groups and its influence on progressive mobility in the adult, critically ill patient on mechanical ventilation has not been examined. Identifying muscle strength in this patient population can benefit overall muscle health and minimize muscle deconditioning through a progressive mobility plan. The objective of this dissertation was to describe muscle strength in different muscle groups and to describe the influence …

5-Ht2b Receptor-Mediated Cardiac Valvulopathy, Pallavi Nistala

Theses and Dissertations

5-HT_2B receptor agonism causes cardiac valvulopathy, a condition characterized by thickening of the heart valves and as a result, regurgitation of blood within the heart. The anti-obesity drug fenfluramine, which was originally prescribed as an anorectic, was withdrawn from the market due to causing cardiac valvulopathy. Fenfluramine, after metabolism by N-dealkylation, produces the metabolite norfenfluramine, which acts as a more potent valvulopathogen. The same was seen with MDMA (ecstasy), a popular drug of abuse, which is metabolized by N-dealkylation to produce MDA, a more potent valvulopathogen. Glennon and co-workers. studied a series of 2,5-dimethoxy-4- substituted phenylisopropylamines (DOX type) hallucinogens …

The Effect Of Biologic Materials And Oral Steroids On Radiographic And Clinical Outcomes Of Horizontal Alveolar Ridge Augmentation., Amy Reichert

Theses and Dissertations

The purpose of this study was to investigate if the addition of biologic materials and/or oral steroids would affect horizontal bone gain, or the bone density of the grafted bone in horizontal alveolar ridge augmentations. A retrospective chart review was completed to assess the clinical and radiographic outcomes of 53 ridge augmentation patients. An average bone gain of 3.6mm of width was found in our study based on radiographic analysis. There were no statistically significant differences found in the linear bone gain with the addition of biologic materials and steroids. A marginally statistically significant difference was found in the bone …

Structural Stress And Otherness: How Do They Influence Psychological Stress?, Christine Dewilde

Theses and Dissertations

Background: The Theory of Cultural Distress offers a framework for understanding the potential outcomes in patients who do not receive care that incorporates their cultural beliefs (DeWilde & Burton, 2017).This study represents initial steps in researching the theory byexploring the layering of stressors that place the patient at risk for Cultural Distress. Methods: Utilized aCross-sectional descriptive correlational analysis of intersecting identities (Structural Stressors), ethnicity-related stressors (Otherness) and ethnic-identity (Otherness) to develop understanding of the potential effects of these variables on psychological stress. Independent variables included intersecting identities, perceived ethnic discrimination, concern for stereotype confirmation, own group conformity pressure, and …

Modulation Of Electron Transport By Metformin In Cardiac Protection: Role Of Complex I, Ahmed Abdul Hussein Mohsin

Theses and Dissertations

Modulation of mitochondrial complex I during reperfusion reduces cardiac injury. Complex I exists in two structural states: active (A) and deactive (D) with transition from A→D during ischemia. Reperfusion reactivates D→A with an increase in ROS production. Metformin preserves the D-Form. Our aim was to study the contribution of maintenance of deactivation of complex I during early reperfusion by metformin to protect against ischemia reperfusion injury. Our results showed that metformin decreased H9c2 cardiomyoblast apoptosis and total cell death following simulated ischemia for six hours followed by reoxygenation for twenty four hours compared to untreated cells. Reactive oxygen species (ROS) …

The Impact Of Mother–Father Relationship, Social Support And Neighborhood Context On Preterm Birth, Timothy O. Ihongbe

Theses and Dissertations

Background: Preterm birth is a major public health concern in the US. Previous studies have suggested that quality of the mother-father relationship, social support, and neighborhood violence may be associated with preterm birth; however, findings are equivocal.

Objectives: The main objectives of this dissertation were: 1) to determine the modifying effect of perceived residential environment on the association between quality of mother–father relationship and preterm birth in a sample of African-American women, 2) to examine whether the receipt of social support modifies the association between neighborhood violence exposure and preterm birth in a nationally representative sample of US women, and …

Assessment Of Pediatric-Focused Brief Motivational Interviewing Training Of Dental Students And Pediatric Dental Residents, Victoria M. Onesty

Theses and Dissertations

Purpose: To assess dental students and pediatric dental residents’ knowledge and attitudes towards motivational interviewing and evaluate the efficacy of a pediatric-focused brief motivational interviewing training program.

Methods: A total of 66 participants were enrolled; 35% were third year dental students, 46% were fourth year dental students and 18% were pediatric dental residents. Participants completed three questionnaires: the first before the training, the second immediately after the training and the third approximately 3.5 months after the training.

Results: A significant increase in correct responses was found for 4 of the 5 questions assessing participants’ knowledge. Participants were satisfied with the …

Potential Antimicrobial Methods For Provisionalizing Teeth After Endodontic Treatment, Laura T. Garden

Theses and Dissertations

POTENTIAL ANTIMICROBIAL METHODS FOR PROVISIONALIZING TEETH AFTER ENDODONTIC TREATMENT

By Laura T. Garden, DDS

A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University.

Virginia Commonwealth University, 2018

Thesis Advisor: Garry Myers, DDS

Department of Endodontics

Objective:To evaluate the effectiveness of a Chlorhexidine soaked cotton pellet on bacterial leakage.

Methods: Fifty-one extracted teeth, including six controls, were instrumented, obturated, and sealed with either a cotton pellet (CP), 2% Chlorhexidine soaked cotton pellet (CHX), or a Permaflo orifice barrier (OB). Each root was suspended between two chambers: the …